Vehicles incorporating a conventional hydrostatic driveline have many benefits over vehicles having a conventional driveline. Such vehicles having the conventional hydrostatic driveline may be well suited for tasks such as pushing loads, lifting loads, or digging, for example. The conventional hydrostatic driveline may provide the vehicle with a high torque output, excellent response to input from an operator, and the ability to power actuators and equipment that may be attached to the vehicle. However, the conventional hydrostatic driveline may result in the vehicle being inefficient, restricted to a narrow speed range, and including specialized, expensive components.
Typically, the conventional hydrostatic driveline is driven by an internal combustion engine. The internal combustion engine is selected to accommodate a peak power demand of the vehicle. Accordingly, the internal combustion engine is oversized for a majority of tasks required of the vehicle, such as moving when the vehicle is in an unloaded state or light tasks. Losses may also be incurred in the conventional hydrostatic driveline itself, through inefficiencies that may be present in hydraulic pumps or other components. Because the internal combustion engine is typically oversized and losses are typically present in the conventional hydrostatic driveline, an efficiency of the vehicle may be compromised.
The high torque output that accompanies the conventional hydrostatic driveline may restrict the vehicle to the narrow speed range. The narrow speed range may be advantageous for the specialized tasks the conventional hydrostatic driveline is well suited for, but such a speed range may severely restrict the vehicle. Traversing long distances for the vehicle may limit productivity and result in dissatisfaction of the operator.
The conventional hydrostatic driveline may include specialized, expensive components, such as large hydraulic pumps, motors, and valving systems manufactured in small quantities. Inclusion of such components in the conventional hydrostatic driveline may greatly increase an initial cost of the vehicle. Further and as a result, a service cost associated with the vehicle may increase greatly. The conventional hydrostatic driveline including specialized, expensive components may greatly increase purchase and maintenance costs of the vehicle.
It would be advantageous to develop a hydrostatic driveline for a vehicle that is efficient, may be operated at a wide range of speeds, and is comprised of components which are easily procured and serviced.